After the attack De Silva was caught on CCTV taking a "cool, calm and collected walk" back to the Earls Court hostel where he was staying to wash his clothes and get rid of evidence.

Met Police

Murder Weapon: The knife used by De Silva to stab Mr Griffiths to death

Footage of him at the hostel about an hour after the murder showed him listening to music, seemingly entirely unaffected by what he had just done.

He was arrested at the Opendoor Housing Trust Hostel three days later.

The court heard that on the morning of November 10, De Silva went into a number of gardens on Hazlebury Road before stealing a pair of bolt croppers from an unlocked garden shed.

Using the tool, he broke a rear window on the basement level of Mr Griffiths' nearby six-storey terraced home and walked around the lower two levels before launching the fatal attack.

Mr Griffiths had been sleeping in a separate bedroom from his wife Judy on the ground floor of the home they had lived in for 50 years while family friends, who were visiting for a wedding, slept on the second floor.

A victim impact statement by his eldest son Mark Griffiths, 53, was previously read out to the court.

"The murder of Joe in such a senseless manner has left a gaping hole not just in our family, but every family who knew him," it said.

"We as a family are living with the devastating consequences of that act of violence."

The court head De Silva has 31 previous convictions from the age of 12 to his arrest for the murder at the age of 19, for matters such as robbery, burglary and carrying a knife.

In 2002, the trial judge, Timothy Pontius, sentenced De Silva's father Emmanuel De Silva to 24 years' imprisonment for robbery.

Court reports at the time said he was part of a gang that was responsible for a number of well planned and executed robberies in the London area between January 2000 and May 2001 and that Emmanuel's nephew, Orson De Silva, was jailed for 24 years for similar offences.

Investigating officer detective inspector Simon Pickford, of the Met's Homicide and Major Crime Command, said: "De Silva is an extremely violent individual who had no hesitation in stabbing the victim repeatedly in a frenzied and brutal attack after he was disturbed having broken into Mr Griffiths' home.

"I must pay tribute to Mr Griffiths' family who have been left utterly devastated by what happened. They have conducted themselves with the utmost restraint and dignity throughout this tragic incident and my and my team's thoughts are with them."